Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.37773
Extinction coefficient k: 0

Permittivity ε₁: 1.89813
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: 106.28
Chromatic dispersion dn/dλ: -0.0184725 µm⁻¹

Group index n_g: 1.38858
Group velocity dispersion: 31.0926 fs²/mm

Dispersion parameter D: -169.626 ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = n − λ dn/dλ, GVD = λ³/(2πc²) d²n/dλ², D = −(λ/c) d²n/dλ². Group-velocity dispersion is given for formula data only.

Use it in Lightsmith

Load this data in Python, simulate in one more line

pip install lightsmith

import lightsmith as ls

# MgF2 (Magnesium fluoride): Li 1980: n(o) 0.14–7.5 µm
mgf2 = ls.fetch_refractiveindex("main", "MgF2", "Li-o", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(mgf2.range_nm)  # (140, 7500) nm
eps = mgf2.eps([633])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_b5a6c05d59ed/lightsmith"
mgf2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(mgf2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (mgf2/li-1980-o).

# ... load mgf2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=mgf2)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_b5a6c05d59ed/lightsmith?model=drude_lorentz"
mgf2_dl = ls.DrudeLorentz.model_validate(json.load(urllib.request.urlopen(url)))

A dispersive Drude–Lorentz model for time-domain solvers.

Materials guide Open a sphere of it in Studio Quick start Ask the community

Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.

Dispersion formula

Sellmeier (formula 1), λ in µm

n^{2} - 1 = 0.2762 + \frac{0.60967 λ^{2}}{λ^{2} - {0.08636}^{2}} + \frac{0.008 λ^{2}}{λ^{2} - {18.0}^{2}} + \frac{2.14973 λ^{2}}{λ^{2} - {25.0}^{2}}

Valid from 0.14 to 7.5 µm.

Coefficients as stored

C_i	Value
C1	0.2762
C2	0.60967
C3	0.08636
C4	0.008
C5	18.0
C6	2.14973
C7	25.0

Comments and conditions

293 K (20 °C). Ordinary ray (o).

Conditions

temperature: 293 K
direction: o

References

H. H. Li. Refractive index of alkaline earth halides and its wavelength and temperature derivatives. J. Phys. Chem. Ref. Data 9, 161-289 (1980) and references therein.
* Sellmeier formula is derived by critical analysis of experimental data from several sources.

doi:10.1063/1.555616 Refractive index of alkaline earth halides and its wavelength and temperature derivatives, Journal of Physical and Chemical Reference Data (1980)

Cite

H. H. Li. Refractive index of alkaline earth halides and its wavelength and temperature derivatives. Journal of Physical and Chemical Reference Data, 9, 161-290 (1980), doi:10.1063/1.555616; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 400 wavelengths, the same grid as the API and the library

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

MgF2 (Magnesium fluoride), Li 1980: n(o) 0.14–7.5 µm: n and k versus wavelength
λ (µm)	n
0.14	1.503424
0.141404	1.499494
0.142822	1.495723
0.144254	1.492101
0.1457	1.48862
0.147161	1.485274
0.148637	1.482054
0.150127	1.478956
0.151633	1.475971
0.153153	1.473095
0.154689	1.470323
0.15624	1.46765
0.157807	1.46507
0.159389	1.462579
0.160988	1.460174
0.162602	1.45785
0.164232	1.455604
0.165879	1.453433
0.167543	1.451332
0.169223	1.4493
0.170919	1.447333
0.172633	1.445428
0.174364	1.443583
0.176113	1.441796
0.177879	1.440064
0.179662	1.438385
0.181464	1.436757
0.183284	1.435177
0.185121	1.433645
0.186978	1.432158
0.188853	1.430715
0.190746	1.429313
0.192659	1.427952
0.194591	1.42663
0.196542	1.425345
0.198513	1.424097
0.200504	1.422883
0.202514	1.421703
0.204545	1.420556
0.206596	1.41944
0.208667	1.418354
0.21076	1.417298
0.212873	1.41627
0.215008	1.41527
0.217164	1.414296
0.219341	1.413348
0.221541	1.412425
0.223762	1.411525
0.226006	1.410649
0.228272	1.409796
0.230561	1.408964
0.232873	1.408154
0.235208	1.407364
0.237567	1.406594
0.239949	1.405844
0.242355	1.405112
0.244785	1.404398
0.24724	1.403702
0.249719	1.403023
0.252223	1.402361
0.254752	1.401715
0.257307	1.401084
0.259887	1.400469
0.262493	1.399869
0.265125	1.399283
0.267784	1.398711
0.270469	1.398152
0.273181	1.397607
0.27592	1.397074
0.278687	1.396555
0.281481	1.396047
0.284304	1.395551
0.287155	1.395066
0.290034	1.394593
0.292942	1.394131
0.29588	1.393679
0.298847	1.393238
0.301843	1.392807
0.30487	1.392385
0.307927	1.391973
0.311015	1.39157
0.314134	1.391177
0.317284	1.390792
0.320465	1.390416
0.323679	1.390048
0.326924	1.389688
0.330202	1.389337
0.333514	1.388993
0.336858	1.388656
0.340236	1.388327
0.343647	1.388006
0.347093	1.387691
0.350574	1.387383
0.354089	1.387081
0.35764	1.386787
0.361226	1.386498
0.364848	1.386216
0.368506	1.38594
0.372202	1.385669
0.375934	1.385405
0.379704	1.385146
0.383511	1.384892
0.387357	1.384644
0.391241	1.384401
0.395164	1.384163
0.399126	1.38393
0.403129	1.383702
0.407171	1.383479
0.411254	1.38326
0.415378	1.383046
0.419543	1.382836
0.42375	1.382631
0.427999	1.382429
0.432291	1.382232
0.436625	1.382039
0.441004	1.381849
0.445426	1.381664
0.449892	1.381482
0.454403	1.381304
0.45896	1.381129
0.463562	1.380958
0.46821	1.38079
0.472905	1.380626
0.477647	1.380465
0.482437	1.380307
0.487275	1.380152
0.492161	1.38
0.497096	1.37985
0.50208	1.379704
0.507115	1.379561
0.5122	1.37942
0.517336	1.379282
0.522524	1.379146
0.527763	1.379014
0.533055	1.378883
0.5384	1.378755
0.543799	1.378629
0.549252	1.378506
0.55476	1.378385
0.560323	1.378266
0.565941	1.378149
0.571616	1.378034
0.577348	1.377922
0.583137	1.377811
0.588985	1.377702
0.594891	1.377595
0.600856	1.37749
0.606881	1.377387
0.612966	1.377285
0.619113	1.377185
0.625321	1.377087
0.631591	1.376991
0.637924	1.376895
0.644321	1.376802
0.650782	1.37671
0.657308	1.376619
0.663899	1.37653
0.670556	1.376443
0.67728	1.376356
0.684071	1.376271
0.690931	1.376187
0.697859	1.376104
0.704857	1.376023
0.711925	1.375943
0.719064	1.375863
0.726274	1.375785
0.733557	1.375708
0.740912	1.375632
0.748342	1.375557
0.755846	1.375483
0.763425	1.37541
0.77108	1.375337
0.778812	1.375266
0.786621	1.375195
0.794509	1.375126
0.802476	1.375056
0.810523	1.374988
0.81865	1.374921
0.826859	1.374854
0.835151	1.374787
0.843525	1.374722
0.851983	1.374657
0.860526	1.374592
0.869155	1.374529
0.877871	1.374465
0.886674	1.374402
0.895565	1.37434
0.904545	1.374278
0.913615	1.374217
0.922776	1.374155
0.932029	1.374095
0.941375	1.374034
0.950815	1.373974
0.960349	1.373914
0.969979	1.373855
0.979705	1.373796
0.989529	1.373736
0.999452	1.373678
1.00947	1.373619
1.0196	1.37356
1.02982	1.373502
1.04015	1.373444
1.05058	1.373385
1.06111	1.373327
1.07175	1.373269
1.0825	1.373211
1.09335	1.373153
1.10432	1.373094
1.11539	1.373036
1.12657	1.372978
1.13787	1.372919
1.14928	1.372861
1.1608	1.372802
1.17244	1.372743
1.1842	1.372684
1.19608	1.372624
1.20807	1.372565
1.22018	1.372505
1.23242	1.372444
1.24478	1.372384
1.25726	1.372323
1.26987	1.372262
1.2826	1.3722
1.29546	1.372138
1.30845	1.372075
1.32157	1.372012
1.33482	1.371948
1.34821	1.371884
1.36173	1.37182
1.37538	1.371754
1.38917	1.371688
1.4031	1.371622
1.41717	1.371555
1.43138	1.371487
1.44574	1.371418
1.46023	1.371349
1.47487	1.371279
1.48966	1.371208
1.5046	1.371136
1.51969	1.371063
1.53493	1.37099
1.55032	1.370915
1.56586	1.37084
1.58157	1.370764
1.59743	1.370686
1.61344	1.370608
1.62962	1.370528
1.64596	1.370448
1.66247	1.370366
1.67914	1.370283
1.69598	1.370199
1.71298	1.370113
1.73016	1.370026
1.74751	1.369938
1.76503	1.369849
1.78273	1.369758
1.80061	1.369666
1.81866	1.369572
1.8369	1.369477
1.85532	1.36938
1.87392	1.369282
1.89271	1.369182
1.91169	1.369081
1.93086	1.368977
1.95022	1.368872
1.96978	1.368765
1.98953	1.368656
2.00948	1.368546
2.02963	1.368433
2.04998	1.368319
2.07054	1.368202
2.0913	1.368084
2.11227	1.367963
2.13345	1.36784
2.15484	1.367715
2.17645	1.367587
2.19827	1.367458
2.22032	1.367325
2.24258	1.367191
2.26507	1.367054
2.28778	1.366914
2.31072	1.366772
2.33389	1.366627
2.3573	1.366479
2.38093	1.366329
2.40481	1.366175
2.42892	1.366019
2.45328	1.36586
2.47788	1.365697
2.50272	1.365532
2.52782	1.365363
2.55317	1.365191
2.57877	1.365016
2.60463	1.364837
2.63075	1.364655
2.65713	1.364469
2.68377	1.364279
2.71068	1.364086
2.73786	1.363889
2.76532	1.363688
2.79304	1.363482
2.82105	1.363273
2.84934	1.36306
2.87791	1.362842
2.90677	1.36262
2.93592	1.362394
2.96536	1.362163
2.99509	1.361927
3.02512	1.361687
3.05546	1.361441
3.0861	1.361191
3.11704	1.360935
3.1483	1.360674
3.17987	1.360408
3.21175	1.360137
3.24396	1.35986
3.27649	1.359577
3.30934	1.359288
3.34253	1.358994
3.37604	1.358693
3.4099	1.358386
3.44409	1.358073
3.47862	1.357753
3.51351	1.357426
3.54874	1.357093
3.58432	1.356752
3.62026	1.356405
3.65657	1.35605
3.69323	1.355688
3.73026	1.355318
3.76767	1.35494
3.80545	1.354555
3.84361	1.354161
3.88215	1.353759
3.92108	1.353348
3.9604	1.352929
4.00011	1.3525
4.04022	1.352063
4.08073	1.351616
4.12165	1.351159
4.16298	1.350693
4.20473	1.350217
4.24689	1.34973
4.28947	1.349233
4.33249	1.348725
4.37593	1.348206
4.41981	1.347676
4.46413	1.347134
4.50889	1.346581
4.5541	1.346015
4.59977	1.345438
4.64589	1.344847
4.69248	1.344243
4.73953	1.343627
4.78706	1.342996
4.83506	1.342352
4.88354	1.341693
4.93251	1.34102
4.98197	1.340332
5.03193	1.339628
5.08239	1.338909
5.13335	1.338173
5.18483	1.337421
5.23682	1.336652
5.28933	1.335866
5.34237	1.335062
5.39594	1.33424
5.45004	1.333399
5.50469	1.332539
5.55989	1.331659
5.61564	1.330759
5.67195	1.329838
5.72883	1.328896
5.78627	1.327933
5.84429	1.326947
5.9029	1.325938
5.96209	1.324905
6.02187	1.323849
6.08226	1.322767
6.14325	1.32166
6.20485	1.320527
6.26707	1.319368
6.32991	1.31818
6.39338	1.316964
6.45749	1.315719
6.52224	1.314444
6.58764	1.313138
6.6537	1.311801
6.72042	1.310431
6.78781	1.309028
6.85587	1.30759
6.92462	1.306117
6.99406	1.304608
7.06419	1.303061
7.13502	1.301475
7.20657	1.29985
7.27883	1.298183
7.35182	1.296475
7.42554	1.294723
7.5	1.292927

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

Plot